I have a photo retouching website to which 85% No-Follow and 15% Do-Follow backlinks pointing to. But I need to know what's the ratio of Do-Follow and No-Follow backlinks that is very helpful for SEO ranking.

It usually looks more natural to Google to have more No-Follow links than Do-Follow. That's why the example you've shown is a completely natural looking Link Profile. Everyone wants to have a bunch of Do Follow links but they should never be more than the No Follow ones. It just doesn't look organic enough.

Personally, I have a website in the fitness niche where I have about 70% dofollow links, and so far the site hasn't been doing that bad (nowadays traffic isn't as high as it used to be once, but that's because I've been ignoring the site for over a year now). So I think Google doesn't really care as long as you have high quality backlinks (I built over 300 high quality, white hat outreach links so I think that's a big plus in Google'y eyes). Here's an Ahrefs screenshot of my backlink profile, you can check out my fitness site as a case study, I don't mind (as long as the mods don't mind it either).

Is there any proportion among dofollow and nofollow back-connections of a site? what's more, Google will have a quite decent understanding what they're up to to your space control, yet they make your backlink profile look common. Nearby Marketing; Business Listings Audit · Citation Cleanup · Local Ranking Factors

I don't think there is any such ratio. And maintaining no-follow is of no use as this does not give any value to the user hence Google does not lay any wait in no-follow links. So as per my experience 98:2 would be fine.

98% do-follow links and 2% no-follow links. In case you suspect the authenticity of the link you are linking to, go for no-follow links.

Why Backlinks are important for your web pages?

Not long ago did having low-quality backlinks was also considered to rank pages by Google. But since the Penguin algorithm update, this game has changed everything. A lot of top-notch bloggers lost the traffic and rank drastically before they could know what has happened.

It took quite a long time to understand the reason the drop. But once understood they did not commit the mistake ever again. Not only having backlinks is important, but having quality backlinks is what matters. If you see backlinks from spam or automated websites, remove it immediately.

Now let’s have a look why having quality backlinks is important.

#1 Increases traffic & organic ranking

With more quality backlinks pointing to your domain the traffic in going to shoot up. As the backlinks bring traffic to your domains your ranking will also be increasing.

Notice, if any of your content is ranked well then surely one of the reasons behind this would be quality backlinks.

#2 Strong signal to Google search crawler

When a search engine encounters a backlink to a domain, it considers your domain to be informative and also worth showing to more people.

And because of the traffic from backlinks search engine again considers your content to be useful and place it over the pages with fewer backlinks.

#3 Builds Domain Authority/Page Authority

Domain authority is score developed by Moz which predicts how well a website would do on SERP and same goes with the page authority.

Higher the DA/PA higher will the quality of backlinks (in case you are seeking backlinks) or higher will the be the rank (in case DA/PA of your web pages are high)

And it is important to know that backlinks from the high-quality website also increase your DA/PA.

#4 Faster indexing

Since you have got high PR backlinks, your content will be indexed faster. Reason being the domain pointing towards yours is already indexed well, so along with that domain, even your content will index well.